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D1 LUCAS WIRING IN A MESS.
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TallGuy
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December 10, 2019 - 10:49 pm
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Hi Folks,

hope you can help me out here. I have a 1952 plunger bantam D1 with lucas electrics, the previous owner who has owned it since 1960 has had it for field use only.

There's no lights, no ignition switch, no kill switch, the electrics are cobbled together under a homemade saddle. The previous owner described the electrics as "electrically, rectifier was replaced with triple diodes and a zener diode"... it was supposed to have been running 5 years ago.

I've not come across a bike wired this way. Looking at the cobbled assembly I can recognise what are the three diodes and  the zenner diode, but the clear plastic part which appears to have a switch wiring diagram on it, and a load of wires attached, I am unsure of.

I'm posting some photo's, hoping someone can put some light onto the subject for me.. hope the photo's aren't too big.

At the moment my thoughts are to replace the lot, although it would be good to just be able to get the bike working as is to test the engine.

Thanks for your thoughts in advance 🙂

Alan.

 

switch4-1.jpg

top4-1.jpg

Zener-diode4-1.jpg

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Stoo63
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December 10, 2019 - 11:33 pm
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Hi Alan, perfect title coz that looks like a right bleedin' mess. The wiring diagram for that set-up only exists in the head of the guy who did it. Not uncommon for someone to have  created  their own "custom" wiring to upgrade the standard system. Personally I've not toyed with the Lucas genny yet but someone will be along to help, I'm sure. Try these in the meantime

** Please log in to view **

** Please log in to view **

Also take a look in the Members Area at service sheets nos. 812 and 812a. 

And ** Please log in to view **

And ** Please log in to view **

At the end of the day you're gonna have to rip it all out but if you can coax a spark out of it, you'll at least know if you've got a runner.

Happy reading

Stewart

'52 D1 direct lighting plunger, '58 Square Four (project), '59 D1 direct lighting plunger,  '59 Tiger Cub, '60 5TA,  '76 FS1-E

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mike p5xbx
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December 11, 2019 - 12:29 am
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all I can tell you is the top photo is a Relay and the bottom a Resister
the wiring is unfathomable to anyone but the person that did it
lots of links to the D1 Lucas system above but i think you will have to start again with it
but you can rewire it a lot easer if you go 12volt and use a 12volt Regulator/ Rectifier

D? - D10- D14 Bantams 350 AJS -500 Triumph http://bsanotru.....lfire.com/

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cocorico
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December 11, 2019 - 7:51 am
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Certainly look to be due a complete rewire. I don't know much about the Lucas system. I do know there is a dire warning about the consequences of separating the rotor / stator. If they are there, you can ignore that - short term anyway - as I think that is in order to prevent the magnetism of the poles from fading, the stator poles act as a 'keeper' for the magnetic poles.

As far as running the engine goes, if you have a battery, a HT coil and a few bits of wire you can 'hot wire' the system. CB of coil to points, + of coil to battery + (as long as you are connecting only to the coil & points polarity doesn't matter), battery - to chassis. Best to connect the battery via a simple switch, or an assistant to hold it connected, in order to not overheat the coil if the points are closed and you forget about it! It's basic, it will flatten the battery over time, but it's OK for testing.

1956 D3 running, lights to sort. 7 other bikes in the Barn. 1950 D1 engine being rebuilt (slowly).

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sunny
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December 11, 2019 - 9:53 am
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i   dont  serpoz   it  helps  much    but  the  parts  on  the photos   remind  me  of   the  1960 s honda   50 cc  stuf

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TallGuy
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December 11, 2019 - 9:01 pm
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Stoo63 said
Hi Alan, perfect title coz that looks like a right bleedin' mess. The wiring diagram for that set-up only exists in the head of the guy who did it. Not uncommon for someone to have  created  their own "custom" wiring to upgrade the standard system. Personally I've not toyed with the Lucas genny yet but someone will be along to help, I'm sure. Try these in the meantime

** Please log in to view **

** Please log in to view **

Also take a look in the Members Area at service sheets nos. 812 and 812a. 

And ** Please log in to view **

And ** Please log in to view **

At the end of the day you're gonna have to rip it all out but if you can coax a spark out of it, you'll at least know if you've got a runner.

Happy reading

Stewart  

Hi Stewart,

thank for the links.. I have been looking at them, plus I have an original 1956 service sheet book that covers the Lucas system..

Just hoped I could get by with what I have for the time being.. since I posted this topic I've had a look at the coil, I have a feeling that's possibly duff.. how to check I'm unsure.. I put a multi meter on it on maximum ohms, tried between centre connection and an outside connection, the needle swung fully across.. tried the same between the two outside connections with the same result.. I don't think it should have done that, but unsure.. a little bit of knowledge is dangerous 🙂

Cheers,

Alan.

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TallGuy
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December 11, 2019 - 9:05 pm
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mike p5xbx said
all I can tell you is the top photo is a Relay and the bottom a Resister
the wiring is unfathomable to anyone but the person that did it
lots of links to the D1 Lucas system above but i think you will have to start again with it
but you can rewire it a lot easer if you go 12volt and use a 12volt Regulator/ Rectifier  

Hi Mike,

thanks for looking and your thoughts.. I like the thought of that 12v system..

Cheers,

Alan.

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TallGuy
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December 11, 2019 - 9:10 pm
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cocorico said
Certainly look to be due a complete rewire. I don't know much about the Lucas system. I do know there is a dire warning about the consequences of separating the rotor / stator. If they are there, you can ignore that - short term anyway - as I think that is in order to prevent the magnetism of the poles from fading, the stator poles act as a 'keeper' for the magnetic poles.

As far as running the engine goes, if you have a battery, a HT coil and a few bits of wire you can 'hot wire' the system. CB of coil to points, + of coil to battery + (as long as you are connecting only to the coil & points polarity doesn't matter), battery - to chassis. Best to connect the battery via a simple switch, or an assistant to hold it connected, in order to not overheat the coil if the points are closed and you forget about it! It's basic, it will flatten the battery over time, but it's OK for testing.  

Hi ** Please log in to view **

Thanks, the generator looks intact, at this point I can't even guarantee that that's working...

Not heard of running a bike straight off a battery, obvious when I think about it.. learn something every day.

Cheers,

Alan.

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TallGuy
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December 11, 2019 - 9:12 pm
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sunny said
i   dont  serpoz   it  helps  much    but  the  parts  on  the photos   remind  me  of   the  1960 s honda   50 cc  stuf  

Hi sunny,

sounds a plausible thought.. it's also nice to know people are looking..

thanks for replying,

Cheers,

Alan.

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chickensoup
Bolton, Greater Manchester
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December 11, 2019 - 10:34 pm
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Hi Tall Guy,

I also own a Lucas D1 Plunger, but mine is running with a later engine. I still have the Lucas 125cc engine and use the Lucas head light and switch. I will also have to do a re-wire once I have re- furbished my 125cc Lucas engine.

If it would help you, I could post some photo's of my headlight/switchgear and some of the other components that incorporate the Lucas system. the only thing I don't have is the old wiring loom, coil and battery.

One thing I know for sure, a Lucas head light complete with the switch will be hard to come by.

Nick

1950 BSA D1 Plunger   242 UYW

1966 BSA D7  LBF 62 D

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TallGuy
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December 11, 2019 - 11:40 pm
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chickensoup said
Hi Tall Guy,

I also own a Lucas D1 Plunger, but mine is running with a later engine. I still have the Lucas 125cc engine and use the Lucas head light and switch. I will also have to do a re-wire once I have re- furbished my 125cc Lucas engine.

If it would help you, I could post some photo's of my headlight/switchgear and some of the other components that incorporate the Lucas system. the only thing I don't have is the old wiring loom, coil and battery.

One thing I know for sure, a Lucas head light complete with the switch will be hard to come by.

Nick  

Hi Nick,

thanks for your offer of help..I'd love an original headlight but find it unlikely that I will get one unless I'm very lucky.. The bike is missing several original items.. mudguards, headlight and bracket, toolbox and battery holder, rear number plate...   I'll more and probably go the 12 volt way, battery less if possible.. find suitable new non original type mudguards and headlight.. I would like a toolbox, I'll have to keep an eye out for one...

..right now, that I've almost decided what to do electrically ( scrap all that I've got ), I need to know how to check the alternator / generator...

 

Cheers for your offer.

Regards,

Alan.

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cocorico
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December 12, 2019 - 7:58 am
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TallGuy said

... I need to know how to check the alternator / generator...

Easiest way is to get the engine running on a hot wire, then measure the output of the generator.

Alternatively, you should have a low resistance across the coils and a decent magnetic attraction from the magnets. So, ohmmeter (Multimeter) for the coils, for the magnets you need to separate rotor from stator and carry out 'the spanner test'.wink This consists of holding a decent sized spanner towards each pole in turn to check that it is pulled to the pole. This is only an estimation of their strength, but should help. EDIT: check before separating stator and rotor. It may cause a drastic loss of magnetism. See following posts.

Then it's back to getting the engine running!

TallGuy said

...I've had a look at the coil, I have a feeling that's possibly duff.. how to check I'm unsure...  

Ign.jpg

The ignition coil has a primary coil and a secondary coil, low resistance on one (+ to -) and high resistance on the other (- to HT socket). If you measure between + and - you should get a few ohms. If you measure between HT and - you should get a reading in 1000s of ohms, you will get a similar between HT and + as there is only the low res coil to add in.

If you connect a circuit as shown, with the breaker points closed, then flick the points open, you should see and hear a spark at the plug. Make sure you don't leave the battery connected for long as the constant current through the coil can overheat it.

hope-that-helps

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1956 D3 running, lights to sort. 7 other bikes in the Barn. 1950 D1 engine being rebuilt (slowly).

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TallGuy
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December 12, 2019 - 1:58 pm
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cocorico said

Ign.jpg

The ignition coil has a primary coil and a secondary coil, low resistance on one (+ to -) and high resistance on the other (- to HT socket). If you measure between + and - you should get a few ohms. If you measure between HT and - you should get a reading in 1000s of ohms, you will get a similar between HT and + as there is only the low res coil to add in.

If you connect a circuit as shown, with the breaker points closed, then flick the points open, you should see and hear a spark at the plug. Make sure you don't leave the battery connected for long as the constant current through the coil can overheat it.

hope-that-helps  

Hi ** Please log in to view **

you've just confirmed my suspicions, the coil is duff.. put multimeter on coil and all positions the reading just flicks to maximum when it's on it's highest setting...   so that means I will have to check my alternator your second way, using the multimeter, as I can't run it without a coil..

 

Great diagrams and clear instructions..  great stuff.. cheers for your help.

Alan.

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mike p5xbx
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December 12, 2019 - 4:10 pm
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cocorico said
for the magnets you need to separate rotor from stator and carry out 'the spanner test'
  

in post 12 above

LUCAS Alternator !
Best to get that bit edited out
and then this post as well

as you correctly said in post 4
“I do know there is a dire warning about the consequences of separating the rotor / stator “

its not worth the risk

D? - D10- D14 Bantams 350 AJS -500 Triumph http://bsanotru.....lfire.com/

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cocorico
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December 12, 2019 - 5:54 pm
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I understand what you're saying, Mike. My view is that if you understand why the warning is there (the magnetism may be lost) and also understand how long it takes for the loss, together with how to prevent it, it is quite possible to take the unit apart and put it back together.

However, your opinion is that it should not be done, perhaps from experience? I did give an alternative way of testing.

For reference, ** Please log in to view ** is the BSA Service sheet, it too says not to dismantle it, though it does imply that a dealer can do it. I don't think items like that were binned by dealers in that era!

1956 D3 running, lights to sort. 7 other bikes in the Barn. 1950 D1 engine being rebuilt (slowly).

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mike p5xbx
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December 12, 2019 - 6:36 pm
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there is also a warning sticker on the alternator itself...
donot.jpeg

if you want to take the risk and try that yourself fine
but I haven’t done it and i take it you haven’t either
I have no idea just how long you could remove the magnetic rotor before it becomes useless
but perhaps not a good idea to suggest it to someone else until you know for sure that removing it and checking magnetic strength with a spanner would not kill the alternator

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cocorico
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December 12, 2019 - 8:47 pm
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All I can add is that I do know that permanent magnets do not immediately lose their magnetism, but do so over a period of time - the stator acts as a keeper for the magnetic field (remember Eclipse horseshoe magnets which always came with a small bar across the poles?). So any rotor (Lucas, Wipac, Moto Morini) will lose their strength if separated from their stators, over time. A suitably sized steel disc can be used as a keeper for long term storage.

No maintenance should be carried out on anything unless the person doing it is aware of what they are doing and possible consequences, but just look at any Owner's Manual these days and you will see that half of it consists of Safety Notices and advice that most maintenance operations should be carried out by Approved Dealers. Now how can we hope to get any maintenance done on our machines?

Apologies to Alan if I have hijacked his post. It was how I would have proceeded with the info available.

1956 D3 running, lights to sort. 7 other bikes in the Barn. 1950 D1 engine being rebuilt (slowly).

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TallGuy
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December 12, 2019 - 10:47 pm
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mike p5xbx said
there is also a warning sticker on the alternator itself...
donot.jpeg

if you want to take the risk and try that yourself fine
but I haven’t done it and i take it you haven’t either
I have no idea just how long you could remove the magnetic rotor before it becomes useless
but perhaps not a good idea to suggest it to someone else until you know for sure that removing it and checking magnetic strength with a spanner would not kill the alternator  

Hi Mike,

thanks for the cautionary words, better safe than sorry.. I know cocorico mentioned the risk earlier on.. still it's nice to know someone is watching my back 😉

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TallGuy
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December 12, 2019 - 10:55 pm
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cocorico said
All I can add is that I do know that permanent magnets do not immediately lose their magnetism, but do so over a period of time - the stator acts as a keeper for the magnetic field (remember Eclipse horseshoe magnets which always came with a small bar across the poles?). So any rotor (Lucas, Wipac, Moto Morini) will lose their strength if separated from their stators, over time. A suitably sized steel disc can be used as a keeper for long term storage.

No maintenance should be carried out on anything unless the person doing it is aware of what they are doing and possible consequences, but just look at any Owner's Manual these days and you will see that half of it consists of Safety Notices and advice that most maintenance operations should be carried out by Approved Dealers. Now how can we hope to get any maintenance done on our machines?

Apologies to Alan if I have hijacked his post. It was how I would have proceeded with the info available.  

No need for apologies, you are trying to help.. I've been considering buying all the other parts for the wiring and just trying to see if it works before messing with the alternator.   Which way to go now is my dilemma, original and 6 volt, or 12 volt direct lighting.. I do like the 12 volt option but looks more complicated using a Lucas generator. Time to ponder as Christmas is near and I have other things / duties to do..

 

Cheers..

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cocorico
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December 13, 2019 - 9:00 am
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Thanks Alan. So, without encouraging you to do anything, ** Please log in to view ** a link to a topic on Lucas systems from some time ago. You may find the photos of the unit and the parts drawings useful.

For basic testing, there appear to be 2 coils on the stator, so you should be able to find a low resistance between the ends of each, together with a link from the end of one to the start of another, so there should also be a low res between the two ends of the coils as they are connected in series - assuming I am reading the diagram correctly. If you have these readings you should be able to get a voltage output when the rotor / engine run.

If your coil is duff, you don't need a special one for test purposes, any Kettering  ignition type coil and battery will do. Sunny is keen on old Honda type 6V coils, I have used a MZ one, an old car coil would work, just a bit bulky for permanent use.

1956 D3 running, lights to sort. 7 other bikes in the Barn. 1950 D1 engine being rebuilt (slowly).

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